- the presence of any red flags (i.e., tumor, metabolic diseases, RA, osteoporosis, prolonged history of steroid use, etc.), or signs consistent with nerve root compression (reproduction of low back or leg pain with straight leg raise at less than 45°, muscle weakness involving a major muscle group of the lower extremity, diminished lower extremity muscle stretch reflex, or diminished or absent sensation to pinprick in any lower extremity dermatome). Other exclusion criteria include prior surgery to the lumbar spine and current pregnancy.